Apparatus and methods for separating solids from flowing liquids or gases

ABSTRACT

An apparatus and method for separating material which includes solid and/or particulate matter from flowing liquid and/or gas. The apparatus includes a separation panel positioned in a fluid flow path, and the separation panel is housed in a separation chamber. Fluid can be introduced into the separation chamber by an inlet to establish a circular flow of the fluid within a confine of the separation panel, so material entrained in the fluid is trapped within the confine of the separation panel. The separation panel, separation chamber and inlet can be dimensioned and disposed such that as the apparatus operates, the flow of the fluid outside the separation panel is in a direction opposite to a direction of the flow of the fluid within the separation panel. The separation panel can include plural deflection means for deflecting material entrained in the fluid away from the openings, and the deflection means are generally opposed to a direction of the flow of the fluid, each opening having one of the deflection means associated therewith.

FIELD OF THE INVENTION

This invention relates to apparatus and methods for separating solids orparticulate matter from flowing liquids or gases. The invention hasparticular, although not exclusive, application to the filtration offloating and entrained solids from discharges of water. One particularapplication of the invention is in relation to storm water draintechnology.

BACKGROUND OF THE INVENTION

There are many applications where it is desirable to separate solidsfrom a flowing liquid. Such applications include the following.

1. Separation of solids from storm water

In many parts of the world, storm water is directed to waterways andseas. Storm water is a major carrier of solid pollutants, such asplastics, cans, tree branches and animal faeces, amongst other things,to waterways and seas.

Endeavours have been made to date, to limit the passage of at least someof these materials to waterways and seas. One method which has been usedis to employ grates across outlets from the drains. This method has beengenerally unsatisfactory because the size of the grate must often besuch as to enable water to pass, even if solid material is held againstthe grate by water pressure. Accordingly, it has been necessary that thegrate be of substantial opening size. A further problem is that evenlarge grates can become blocked, and it is essential to provide a flowpath around or over the grate to prevent build up of water upstream inthe drainage system. A second alternative proposed has been the use ofsystems, such as cyclones and dynamic separators, to remove the waste.While these can be efficient in some circumstances, they are often tooexpensive to be used in the whole of a storm water drainage system.

2. Separation of liquid from sewerage

A major difficulty with many sewerage plants is the sheer volume ofliquid to be handled. This is aggravated where a "mixed" system, thatis, a system which carries both sewerage and storm water, is used. Inmany cases, sewerage plants could handle more sewerage if the quantityof liquid delivered could be reduced. This could occur if, for example,liquid was removed from the sewerage before it enters into trunk sewers.To date, this has not been considered feasible.

Further, there are also many regions in the world where storm water andsewerage are received by the same system. This can cause difficultieswhere there are heavy rains which overload the system, as it isundesirable to permit raw sewerage to pass to overflow.

3. Removal of pollutants from industrial wastes

Many industrial plants must pay prohibitive rates to discharge pollutedliquids into sewers. It would be most desirable to separate a part ofthe pollution before the waste is delivered to sewers, and this willprovide economies both to the plant and to the authority, if the cost ofthe earlier removal of polluted matter was less than the cost ofcleaning up pollution at a later time.

These are merely illustrations of the many uses to which an apparatus ormethod for separating solids from a flowing liquid, could be put. Thereare many other such applications which could be described.

In our International Patent Application number PCT/AU94/00061, wedisclosed and claimed apparatus and methods for separating solids fromflowing liquids. We believe that the apparatus and methods disclosed inthat application provide very good results in applications requiring theseparation of solids from flowing liquids. We have now developedimprovements and/or refinements to the invention disclosed in thatapplication, which we believe provide even better results than thosedisclosed in our earlier application.

SUMMARY OF THE INVENTION

The present invention generally provides an apparatus for separatingsolid or particulate matter from a flowing liquid or gas, the apparatusincluding:

a separation panel positioned in the path of flow of the liquid or gas,the separation panel including a plurality of openings, wherein theopenings are of a predetermined size such that only solid or particulatematter smaller than that size is able to pass through the openings, andwherein further, the configuration and arrangement of the openings onthe separation panel is such that in use of the apparatus, solid orparticulate matter larger than the predetermined size is substantiallyprevented from adhering to or obstructing the separation panel.

Preferably, the arrangement of the openings in the separation panel issuch that, in use of the apparatus, the openings are disposed at anangle relative to the direction of flow of the liquid or gas.

Preferably further, the configuration of the openings is such that eachopening includes a deflection means generally opposed to the directionof flow of the liquid or gas, to assist in deflecting solid orparticulate matter entrained in the flow, away from the openings. In apreferred form of the invention, the separation panel takes the form ofa curved structure.

It is particularly preferred that the apparatus includes a generallycylindrical separation panel. It is particularly preferred that theseparation panel is in the form of an open ended generally cylindricalstructure. In this preferred form of the invention, it is also preferredthat the separation panel forms part of a larger separation chamber,into which, in use of the apparatus, the liquid or gas flow isintroduced by an inlet means, so as to establish a circular flow of theliquid or gas within the separation panel. This circular flow enablessolids or particulate matter of a predetermined size entrained in theliquid or gas, to be trapped and to circulate within the confines of theseparation panel. The circular motion of the flowing liquid or gaswithin the separation panel also results in the entrained solids orparticulate matter generally not adhering to the separation panel, butbeing entrained in the circular motion of the liquid or gas. In thisway, the establishment of a circular flow motion of the gas or liquidwithin the separation panel is such as to enable the separation panel toact as a generally self-cleaning filter for the solid or particulatematter entrained within the flowing liquid or gas. The fact that theliquid or gas is able to pass freely through the openings in theseparation panel means that the panel is able to filter solid orparticulate matter of a predetermined size from the flowing liquid orgas, thereby enabling the liquid or gas to be discharged to an outletmeans, at least substantially filtered of the solid or particulatematter.

It is also preferred that the configuration of the apparatus is suchthat in use, the flow of the liquid or gas outside the confines of theseparation panel is in a direction opposite to the direction of flow ofthe liquid or gas within the confines of the separation panel. Such aconfiguration assists in maintaining the self-cleaning function of theseparation panel, in use of the apparatus.

Preferably, the apparatus also includes means for facilitating thecollection of the solid or particulate matter into a receptacle, fromwhich it may be removed. In some embodiments of the invention,gravitational forces may combine with the circular motion of the gas orliquid within the cylindrical separation panel, so as generally toencourage the deposition of the solid or particulate matter into areceptacle which may be positioned generally below and/or above theseparation panel, depending upon the specific gravity of the solid orparticulate matter. In the case of solids or particulate matter having alower specific gravity than the liquid or gas, they will tend to floaton the surface of the liquid or gas, in which case, they can becollected by a receptacle generally disposed above the separation panel.In the case of solids or particulate matter having a higher specificgravity than the liquid or gas, they will tend to settle under theaction of gravitational forces, in which case, a receptacle to capturethem will generally be positioned below the separation panel.

The apparatus may also include mechanical means to assist the depositionof the solid or particulate matter in the receptacle, through the actionof gravity. Such means could take any number of forms, but wouldinclude, for example, providing the receptacle with a baffle or flangedirected downwardly to encourage the deposition of settleable solid orparticulate matter.

The invention also provides a method for separating solid or particulatematter from a flowing liquid or gas, the method including the steps of:

positioning a separation apparatus in the path of flow of the liquid orgas; and

providing the separation apparatus with a separation panel having aplurality of openings therethrough, wherein the openings are of apredetermined size such that only solid or particulate matter smallerthan that size is able to pass through the openings, and whereinfurther, the configuration and arrangement of the openings on theseparation panel is such that in use of the apparatus, solid orparticulate matter larger than the predetermined size is substantiallyprevented from adhering to, or obstructing the separation panel.

Preferably further, in the method, the arrangement of the openings issuch that, in use of the apparatus, the openings are disposed at anangle relative to the direction of flow of the liquid or gas.

It is also preferred, in the method, that each of the openings includesa deflection means generally opposed to the direction of flow of theliquid or gas, to assist in deflecting solid or particulate matterentrained in the flow, away from the opening.

Preferably, in the method described above, the separation panel takesthe form of a curved structure.

Preferably further, in the method described above, the separation paneltakes the form of a generally cylindrical structure, and the separationapparatus includes inlet and outlet means for directing the flow ofliquid or gas into, and out of, the separation apparatus respectively.It is particularly preferred that the separation panel is an open endedgenerally cylindrical structure.

It is particularly preferred, in the said method, that the arrangementis such that the liquid or gas is introduced into the separationapparatus via the inlet means and presented to a separation chamberwhich includes a generally cylindrical separation panel, so that acircular motion of the liquid or gas is established within the confinesof the separation panel, so as generally to trap solid or particulatematter of a pre-determined size within the separation panel, yet at thesame time, permit the liquid or gas to pass therethrough freely, and sothat the separation panel is continually cleaned by the circular motionof the liquid or gas within it.

Preferably further, in the method, the configuration of the apparatus issuch that in use, the flow of the liquid or gas outside the confines ofthe separation panel is in a direction opposite to the direction of flowof the liquid or gas within the confines of the separation panel, so asto assist in maintaining the self-cleaning function of the separationpanel, in use of the apparatus.

Preferably further, the method also includes the step of providing meansto facilitate the collection of the solid or particulate matterseparated by the method, from the flowing liquid or gas. Such meanscould, for example, utilise the assistance of gravitational forces, toassist in the collection of the solid or particulate matter.

Preferably further, the method also includes means for facilitating theremoval from the separation apparatus, of solids or particulate matterseparated from the flowing liquid or gas.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In order that the invention may be further understood, we will nowdescribe preferred embodiments of it, by way of example only, withreference to the accompanying drawings, in which:

FIG. 1 is a plan view of one example of a separator made in accordancewith the invention;

FIG. 2 represents a view (in the direction of the arrow marked "B" inFIG. 1) of a vertical section of the separator shown in FIG. 1, takenalong the line 2--2 in that Figure;

FIG. 3 shows an enlarged horizontal section of part of a separator panelfor use in the invention; and

FIG. 4 is a view from the side of a vertical section through anexemplary separator made in accordance with the invention.

Referring now to the accompanying drawings, FIG. 1 shows a plan view ofan apparatus which could be used to separate solids from a flowingliquid, such as water (and particularly, storm water). The apparatusshown, generally denoted 25, includes a separation panel 1, which asdepicted, is of a generally circular shape, when viewed in horizontalcross-section. When viewed in three dimensions (as shown moreparticularly in FIG. 2), it can be seen that the separation panel 1 hasan open-ended generally cylindrical configuration.

As shown in FIGS. 1 and 2, the separation panel 1 is located within aseparation chamber 2. The liquid enters the separation apparatus 25 viaan inlet means 3, in the direction of the arrow 27 shown in FIG. 1. Asshown in FIG. 1, the inlet channel 3 curves to the left until reachingthe body 37 of the separator 25, where water and entrained solids orparticulate matter are presented through an opening 8 into the interior19 of the separation panel 1. The generally cylindrical configuration ofthe separation panel 1 is such that when the water leaves the opening 8and enters the interior (or confines) 19 of the separation panel 1, acircular flow motion is established within the confines 19 of theseparation panel 1, in the direction shown by the arrow 29 shown in FIG.1.

Referring now to FIG. 3, it will be seen that the exemplary separationpanel 1 depicted consists of a number of deflection means in the form ofsolid deflective segments 10 which generally present a closed face tothe direction of flow of the liquid (as shown by the arrow numbered 31in FIG. 3) within the separation panel 1. Behind each deflective segment10 in the separation panel, there is an opening 9. As illustrated, eachopening 9 is disposed at an angle to the direction of flow of the liquidin the separation panel 1. Moreover, the openings 9 are all of apredetermined size, which is such as to permit the passage only ofparticulate matter smaller in size than that of the openings. The liquidis of course, also able to pass freely through the openings. In use ofthe separation apparatus 25, the effect of this arrangement of featuresis that only the liquid, and solids or particulate matter of a sizesmaller than that of the openings 9 are able to pass through theseparation panel. Solids or particulate matter of a larger size aretherefore trapped within the confines 19 of the separation panel.Moreover, the circular motion of the liquid within the confines 19 ofthe separation panel means that trapped solids or particles arecontinuously deflected from the interior wall 33 of the separationpanel. The net effect of this arrangement is therefore that theseparation panel 1 is substantially self-cleaning.

Solids trapped within the confines 19 of the separation panel aretherefore caused to continue moving by the circular flow until theysettle under gravity, or, if floatable, are retained on the surface. Atthe same time, untrapped solids and the liquid are able to pass throughthe separation panel into the upper portion 5 of the separation chamber2, and thence to the outlet means 6 (which, as shown in FIG. 1, may takethe form of a channel, pipe or other suitable outlet structure).

As shown in FIG. 3, preferably, the flow of the liquid or gas outsidethe confines of the separation panel is in a direction opposite to thedirection of its flow within confines. This counter-current flow motionon opposite sides of the separation panel establishes a kineticequilibrium which in turn facilitates the generally self-cleaningfunction of the circular flow motion established within the confines 19of the separation panel.

As shown in FIGS. 2 and 4, the separation apparatus 25 may also includea receptacle 4, such as a collection sump, for the containment (andremoval, if desired) of settleable solids. The sump 4 may be sized orconfigured so as to slow down the circular flow of the liquid at thelower portion of the apparatus 25, so as to facilitate settlement ofsolids. The sump 4 may also be provided with any suitable means tofacilitate the removal of settled solid or particulate matter. Suchmeans could include, for example, periodic removal by education, or amechanical bucket or basket that is suspended in the sump. Floatableswhich are left floating on the top of the body of water treated by theseparation apparatus 25 could be removed by any convenient means.

As shown more particularly in FIG. 4, the separation apparatus may alsoinclude means for assisting the settlement of solids into the sump 4.The means shown in FIG. 4 take the form of a downwardly directed annularflange or baffle 17, which assists in directing downwardly moving solidsinto sump 4. The flange or baffle 17 also substantially prevents thecircular motion of the liquid or gas within the upper regions of theseparation chamber from being transferred into the sump 4.

Referring now to FIG. 2, as illustrated, the cylindrical separationpanel 1 may be fitted with a continuation part 7 of the same material(or of another, generally impervious material) above the level of thenormal inlet flow. This continuation part 7 ensures the retention offloating solids if the separation apparatus is subjected to headpressure (eg during flood conditions), if the apparatus is being used,for example, for the removal of litter from urban stormwater runoff.

Where particularly "purified" liquids or gases are required at theconclusion of the filiation procedure, it is possible for the outletfrom one separation apparatus according to the invention to feed intothe inlet for a second such separator, and therefore, for the liquid orgas to be filtered sequentially by two or more such separators, arrangedin series. In such an arrangement, the size of the openings in theseparation panels for the second and subsequent separators could besequentially (and increasingly) smaller, so that each subsequentseparator removes increasingly finer particles. Hence, by thisarrangement, very high, or indeed, any desired level of filtration orpurification could be achieved.

While much of the aforegoing description of the preferred embodimentshas been concerned with apparatus for separating solids entrained inliquids, it is to be understood that the invention is equally applicableto the separation of solids entrained in gases. Generally, for moreefficient operation of gas/solid separators constructed in accordancewith the invention, it would be necessary for the separator to beconstructed as a sealed unit, so as to prevent the undesired escape ofgases undergoing filtration. (This is a feature which could also beutilised in some liquid/solid separators constructed in accordance withthe present invention). In this way, solid matter entrained in exhaustgases and gaseous emissions from various manufacturing plants, could befiltered in much the same way as solid-bearing liquids are treated,using the apparatus and methods of the present invention.

Those skilled in the art will therefore readily appreciate that theapparatus and methods of the present invention are capable of being putto many different uses, and that they embrace many modifications andvariations. It is therefore also to be understood that the spirit andscope of the present invention is in no way limited to the particulardetails of the preferred embodiments described herein, but extends to,and is to be determined by reference to each novel feature andcombination of features defined by the appended claims.

We claim:
 1. An apparatus for separating a material comprising at leastone of a solid matter and a particulate matter from a fluid comprisingat least one of a flowing liquid and a flowing gas, the apparatuscomprising:a separation panel having a concave inner side defining aconfine and said panel having a convex outer side, said separation panelbeing positioned in a path of a flow of the fluid, the separation panelincluding a plurality of openings, wherein the openings are of apredetermined size such that only the material which is smaller thanthat size passes through the openings, and wherein further, the openingson the separation panel have a configuration and an arrangement suchthat the material that is larger than the predetermined size issubstantially prevented from at least one of adhering to and obstructingthe separation panel; and a separation chamber which houses theseparation panel, inlet means for introducing the fluid containing saidmaterial into the separation chamber ans into the confine of the coarseinner side of the separation panel so as to establish a circular flow ofthe fluid within said confine of the separation panel, whereby thematerial of at least the predetermined size entrained in the fluid istrapped within the confine of the separation panel while the fluidpasses through the separation panel, wherein the separation panel, theseparation chamber and the inlet means are dimensioned and disposed suchthat as the apparatus operates, the separation panel is self-cleaning,and wherein the separation panel, the separation chamber and the inletmeans are dimensioned and disposed such that as the apparatus operates,the flow of the fluid on the convex outer side of the separation panelwhich is outside the confine of the separation panel is in a directionopposite to a direction of the flow of the fluid on the concave innerside of the separation panel which is within the confine of theseparation panel, so as to contribute to the self-cleaning of theseparation panel and wherein said apparatus further comprises collectingmeans positioned below the separation panel for collecting the materialthat is trapped within the confine of the separation panel.
 2. Anapparatus as claimed in claim 1, wherein the separation panel is in theform of a generally cylindrical structure.
 3. An apparatus as claimed inclaim 1, wherein the separation panel is an open ended generallycylindrical structure.
 4. An apparatus as claimed in claim 1, whereinthe arrangement of the openings in the separation panel is such that theopenings are disposed at an angle relative to the flow of the fluid. 5.An apparatus as claimed in claim 1, wherein the collecting meanscomprises a biasing means for biasing which utilises a gravitationalforce to encourage settlement of settleable said material.
 6. Anapparatus as claimed in claim 5, wherein the biasing means comprises atleast one downwardly directed baffle or flange which encouragesdeposition of settleable said material.
 7. An apparatus as claimed inclaim 1, wherein the collecting means further comprises a receptacle forcollecting the material.
 8. An apparatus as claimed in claim 7, whereinthe apparatus additionally includes removing means for removing thematerial from the receptacle.
 9. An apparatus as claimed in claim 8,wherein the removing means for removing the material from the receptaclecomprises a removable container provided with the receptacle into whichthe material is received during use of the apparatus.
 10. A method forseparating a material comprising at least one of a solid matter and aparticulate matter from a fluid comprising at least one of a flowingliquid and a flowing gas, the method including the step of:positioning aseparation apparatus in a path of a flow of the fluid, the separationapparatus comprising a separation panel having a concave inner sidedefining a confine and said panel having a convex outer side, saidseparation panel having a plurality of openings therethrough, whereinthe openings are of a predetermined size such that only the materialwhich is smaller than that size passes through the openings, and whereinfurther, the openings on the separation panel have a configuration andan arrangement such that the material that is larger than thepredetermined size is substantially prevented from at least one ofadhering to and obstructing the separation panel, and a separationchamber which houses the separation panel; introducing the fluid intothe separation chamber and into the confine of the concave inner side ofthe separation panel by an inlet means so as to establish a circularflow of the fluid within said confine of the separation panel, wherebythe material of at least the predetermined size entrained in the fluidis trapped within the confine of the separation panel while the fluidpasses through said separation panel, wherein the separation panel, theseparation chamber and the inlet means are dimensioned and disposed suchthat as the apparatus operates, the separation panel is self-cleaning,and wherein the separation panel, the separation chamber and the inletmeans are dimensioned and disposed such that as the separation apparatusoperates, the flow of the fluid on the convex side of the separationpanel which is outside the confine of the separation panel is in adirection opposite to a direction of flow of the fluid on the concaveside of the separation panel which is within the confine of theseparation panel, so as to contribute to a self-cleaning function of theseparation panel and collecting the material that is trapped within theconfine by means of a collecting means positioned below the separationpanel.
 11. A method as claimed in claim 10, wherein the separation panelis in the form of a generally cylindrical structure.
 12. A method asclaimed in claim 10, wherein the separation panel is an open endedgenerally cylindrical structure.
 13. A method as claimed in claim 10,wherein the arrangement of the openings in the separation panel is suchthat the openings are disposed at an angle relative to the flow of thefluid.
 14. A method as claimed in claim 10, wherein the collecting isperformed by biasing the material using a gravitational force toencourage settlement of settleable said material.
 15. A method asclaimed in claim 14, wherein the biasing is caused by providing at leastone downwardly directed baffle or flange which encourages deposition ofsettleable said material.
 16. A method as claimed in claim 10, whereinthe collection means further comprises a receptacle for collecting thematerial.
 17. A method as claimed in claim 16, further comprising thestep of removing the material from the receptacle.
 18. A method asclaimed in claim 17, wherein the removing of the material from thereceptacle is performed using a removable container provided with thereceptacle into which the material is received during use of theapparatus.